How to make camera viewport fit in a window?

So, I have my UI, and I want my camera viewport to fit in the remaining part of my screen. I did it for one resolution, but when I scale game window, things get broken.

Here is how it looks when it’s ok:

And when I scale window:

I want my camera to fit in this “empty” area with any resolution.

Alright, so here is my solution:

using UnityEngine;
using System.Collections;

public class CamVPFit : MonoBehaviour {

	float height, UIPheight;
	public GameObject UIPanel;

	void Start () {
		UIPheight = UIPanel.GetComponent<RectTransform>().rect.height;
		height = Screen.height*1.0f;
		Camera.main.rect = new Rect (0,UIPheight/height,1,1);
	}
}

Works just perfect.